Engine.



PATENTED JAN. 22, 1907.

A. BALL & T. OFFICER.

ENGINE.

APPLICATION FILED MAR.6.1905.

2 SHEETS-SHEET 1.

Wm NQ No. 842,127. PATENTED JAN. 22,1907. A. BALL & "3. OFFICER.

ENGINE.

APPLIGATION FILED MAR-.6.1905.

2 SHEETS-SHEET 2.

wifmessa's,

= Tie/0 8 UNITED STATES PATENT not.

ALBERT BALL AND 'IHOMASv OFFICER. OF GLAREMONT. NEWHAMP- SHIRE, ASSIONORS TO SULLIVAN MACHINERY COMPANY, OF CLARE- NEW HAMPSHIRE, A CORPORATION OF MAINE.

ENGINE.

To all whom zit may concern:

,upon the reverse piston side.

portsin the walls of Be it known that We, ALBERT BALLand THoMAs Orrronn, citizens of the Unlted States, and residents, of Claremont, New

in Engines, of which the following description, in connection with the accompanying drawings, is a specification, like letters on the drawings representing like parts.

Our invention consists in improvements in engines, and more particularly, though not exclusively,in improvements in direct-acting engines of the differential typesuch for example, as are ordinarily employed in connection with rock-drills. This application,

so far as it relates to Figs. 1 to 6, inclusive, discloses matter presented in our prior copending application, filed July 26, 1904, iSerial-No.218,300. r

In the particular embodiment by. which we have here illustrated our invention the engine isof the so-callezl differential type employing a constantly-admitted fluid-pressure supplied at one side of the piston, the working stroke of the piston be ng effected by the intermittent admission oi pressure to the opposite side of the piston and there acting upon a greater etl'ective piston area than Such-engines are commonly of the so-ealledvalveless type, the achnission to and the exhaust from the working end. of the cylinder being effected by-the uncovering of admission anthexhaust the cylinder. A usual construction is an admissionort to the working end of the cylinder connected by a run-around port v. "lithe tool end and a sepa% rate exhaust-port. In prior constructions of differential v'alveless engines it has been impossible to obtain an effective or prolonged working stroke, owing to limitations which are imposed 'in the location of the cylinderports.

- 'Ifthe exhaust-port is located too. near the run-around port, it will be closed too early on the return piston-stroke, and the resulting compression will tend to bring the piston to rest before admission can take placethrough the subse uent uncovering port. If located too remotely from the'rmr Specification of Application filed March 6, I905. Serial'No. 248,509.

' Hampshire, have invented an Improvement of the run-around:

- the admission ingrframe.

Letters Patent. Patented Jan. 22, 1997.

around port, it will be openedtoo soon after cut off on the Working stroke and before opportunity is given for suliicient expansion of the pressure.

We have shown in the drawings an engine of the d rect-acting differential type wherein and exhaust on the working endof the cylinder are controlled by the piston but additional means are also employed to cooperate with the piston to' control the time relation between the exhaust and act mission, so that the closing of the exhaustpassage on the return piston-stroke may be materially delayed and herein until the point of admission is reached, the opening of the exhaust-passage on the working stroke being also delayed, if desired, until the piston has reached a point comparatively remote from the exhaust-port, thereby delaying the exhaust and permittiln any desired degree of expansion to take p ace.- Through our invention the exhaust-port may be-located, if desired,at the end of the cylmder and Without reference to the run-aroum'i port, and the length and effectiveness of the piston-stroke may be very great] I increased. a

Our invention Wi i be best understood from the following description, when taken in connection with the accompanying illustrations of one specific embodiment thereof, while its sco )e will be more particularly pointed out in the appended claims.

In the drawings, Figure 1 is a central longitudinal section taken through the enginecylinder, showing one position of the piston.

'Fig. 2 is a similar view showing another 0- sition of the piston. Fig. 3' shows a modi ied form ofauxil'iary valve. Fig. 4 is a plan view of the cylindcncasting, showing the airpassages. Fig. 5 is arr-elevation showing the connection and relation of the engine illustrated in the preceding figures to its support- Fig. 6 is a fragmentary view looking from the rear of Fig. 5 to show the pressure-suppl t conduit. Fig. 7 is a sectional View of th modified arrangement of the exhaust paa sa e, and Fig. 8 is an end view of the same.

eferring to the drawings and particularly to Figs. 5 and 6, the cylinder A of the engine e engine-cylinder, showing a I the latter is provided with cylinder-heads 0 embodying the illustrated form of my invention is connected with the frame-rods b l) by laLerally-extending ears 0 a. Thecyliuder, with the drill-tool a, may be slid lengthwise the said rods to feed the tr'ioltoward and from the work by rackhnd-piuicn feeding mech anism B, operated through hand-lever d. The arrangement and relationof these parts form no part of the invention claimed in this application, and so far they present features of novelty they are referred to and claimed in our aforesaid prior application.

At the uppermost end of the supporting frame is a holding member e, orovided with a conduit for receiving the supply of fluid under pressure, which herein is assumed to be air. During the operation of the drill air is supplied through suitable connections from the source of supply (not shown) to the mouth e of the holding member, thence to the depending leg 6 its admission to the passage t erein being controlled by the rotary hand-valve], so located as to be conveniently manipulated'by the thumb'and finger of that hand grasping the said holding member.

From the leg c it passes into a chamber in the o'll'set portion e and thence through a sta tionary pipe 6 Fig. 6, to the pressure-chambcr e of the engine-cylin'd er. in entering the pressure-chamber the pipe 6 passes through a suitable stu'lling-box and is extended into the chamber for a sullicient length to permit the necessary movement of the cylinder to take place along the rods 12'?) during the feeding of the drill.

Referring now more particularly to the internal construction of the enginecyliniler,

g, which, togcthcrwith the tiero .lsg g and the recoil-spring 9 9?, employed yieldably to draw the cylintier-heads together, are of a construction usual in this class of apparatus.

Referring to Figs. 1, '2, and 4, the air is constantly admitted to the cylind through the open passage g from the 3.,ressure-chann ber e, tending thereby to return the piston to the position. shown in Fig. 1. On its upward travel the piston uncovers the run around port it, admitting air, as afterward described, through the port It to the working end of the piston. The latter having greater eilective working area than that ol the tool end of the piston, the momentum of the up- I wardly-mo ing piston is overcome and the drill starts on its reverse Working stroke. lnterposeil between the ports h and h is a (liil'ercntial piston-valve 7L2, having a head h, slid able in a cylindrical chamber h, the opposite end of which is connected with the airchamber a through a passage 71. The differential valve 71 at the commencement of the working pistonetroke is held in. the position shown in Fig. 1 by the pressure admitted through the port 72 which, acting on the head 7L2 of greater area, overcomes the pressure ad cylinder until the port it is uncovered.

inodiatcly after this the vent-opening itself is mitted through the duct 7?, the latter acting on the head h of relatively smaller area.

The valve if will be maintained in the position shown in Fig. l on the working stroke of the piston until the latter has traveled far enough to expand the Working fluid below a critical. point, such that the pressure acting on the head 7L2 is no longer sullicient to overcome that acting upon the head 7L3. Vl hen this point is reached, the valve moves to the position shown in Fig. 2, intercepting communication between theports h and h and opening the latter to the exhaust-passage 72 thereby permitting exhaust from. the Working end of the cylinder. The critical point determining the timing of the exhaust Will obviously depend upon the relative areas of the differential heads a and head 7L3. Increasing the dillerence in the areas will retard the opening ofthe exhaust-passage and prolongthe piston-stroke, While decreasing the difference in the two areas will advance the exhaust and shorten the piston-stroke. By suitably proportioning the differential valve the stro re ofthe piston may be varied Within wide limits.

After exhaust has taken place and the momentum of the piston overcome the upward stroke of the piston commences, but the valve it remains in. the position shown in Fig. 2 to permit exit from the cylinder of the air in front of the upwardly-1noving piston until the piston has moved past and uncovered the port h, whereupon the livepressure adn iitted thereto forces the differential valve 72/ upward into the admission position shown in l'ig. 1, closing the exhaust-passage and permitting the live pressure in the run-around to enter the working end of the cylinder through theport 7b. The piston continues moving upward until the momentum has been overcome and then returns on the Working stroke, as before described.

Although it is unnecessary for the opera tion of the engine in practice, We prefer to connect the cylinder to the port It by means such as the vent-opening if, since we have found that continued use is apt to cause such wear that a leakage from the tool end of the cylinder to the port It will sometimes occur before the latter has been actually uncovered )y the piston on its upward stroke, with the result of prematurely raising the pistonvalve 71? to its admission position. The ventopening 71 equalizes the pressure in the port it with the pressure in the working end oflthe closed by the upward travel of the piston. By the use of the auxiliary or differential valve shown the several events of the pistonstroke are controlled by the piston, as is usual with a ditl'erential engine; but the actual timing of the exhaust is controlled through the cooperation of the piston with the Where it enters and leaves the cylinder stuifits reciprocation.

' rod at the through the actual coverlngpr uncovering of constant the efl'ective area of the valve exeaa, rev

run-around port It h stead-of, as heretofore,-

the exhaust-port h by the piston.

Although in practice We prefer to employ differential fluid-pressures, as described, for operatingthe controlling' valve, since variatrons in one pressure are substantially neutraliz'ed by variations in the other, nevertheless any suitable means for differentially act in% upon the valve may be employed.

n the form of auxiliary valve shown in Fig. 2 the valve When'in the exhaust position rests upon the stop it and inthat position is therefore subject to a lesser pressure than when lifted into the position shown in Fi 1, where a'greater area is exposed to the liftin 7 pressure. In Fig. 3 we have" shown a mode fied form of valve, which is similar to that shown in Fig. 2, but provided in place of the stop 7L8 with a plunger h, which moves Within the vented chamber h This maintains posed to pressure admitted to the port it and insures quicker closing of the valve when once the. pressure in the port it has been reduced.

, In Figs. 7 and-8 we have shown a modified arrangement of discharge-passages for the hxhaust. The exhaust-passage it instead of leading directly into the atmosphere dis-- charges into the chamber is, formed by the surrounding shell Fe. The exhaust passes downward into the annular chamber In", surrounding the piston, and is dischargedto the annularopening k down and about the on posed body of the piston-rod at the point lug-box. This arrangement kegps the exposed portion of the piston-rod. free from the dirtanddust which the cutting-tool throws up and. the piston-rod tends to pick up in It also utilizes particles of oil which are inevitably carried out with the'exhau st byeau sing them to impinge on the piston-rod and to be used in lubricating the same. f

The lip 7: projects beneath the dischargeopening it and partially encircles the piston-- side on which the operator stands inorder to prevent the discharged exhaust from spreading in his direction. N

Tin-the modification illustrated the nose of the cylinder-casting is shown as formed in a separate piece 7c, and the piston-packing h" is compressed between a shoulder in the said nose and a gland it, thewh'ole forming a simple and eflectivestufiing-boX when the nose 7c is bolted to the cylinder-casting.

l Ve here'deenr-itunnecessary to refer to the various modifications in -i'orn1, details, and arrangement .of parts which may be. made inthefdr lot our inventibn here disclosed and whichwill be obvious to those skilled in the art, no'r do we deem it necessary to r fer to the variouspbvious applica.

tions which may be made of our invention other than those here referred to, but have a piston movable therein, one side of said piston being in constant communication with the source of fluid-pressure supply, and a valve-controlled port in the cylinder-walls communicating with the other side of said piston, saidport being opened by the piston to admit pressure to the rear end of the cylinder on rearward movement of 'the piston and closed thereby in its movement in the other direction.

2. A differential engine having constantlyadmitted pressure at one side oi the piston and a differential valve having constant pressure upon a pressure area thereof, but adapted to be moved by, pressure admitted from the constant-pressure end of the cylinder and under control of the piston for admitting pressure to the opposite side of the piston.

3. A differential engine having a constantly-admitted pressure at one end of the cylinder, a piston-controlled port at the admissionend thereof and communicating wit the opposite end thereof, a diiierential valve in said port and an exhaust-port or the opposite cylinder end, said piston-controlled port and exhaust-port being separated by a space at least as great as the length of the piston.

4. An engine rovided with a cylinder and a piston movable therein, a cylinder-p0rt controlled by said piston means for adn1itting fluid-pressure to one side thereof, an exhaust-passage for the opposite piston side,

and a difierentially-controlled valve for alternately connecting said opposite side to said cylinder-port and said ex 1aust-passage 5. A. direct-acting engine provided with a differential piston, the smaller areaof which is subject to a constantly-actin pressure, a pressure-passe e leading from the constantpressure end 0 said cyhnrher to the opposite end thereof, a differential valve controlling said passage, the smaller area of said valve being exposed to a constant pressure and tending to "move the valve to a position exhausting pressure from the larger piston area and closing the same to the pressure-passage, and the larger area of said'valve being exposed to the pressure admitted to said pressure-passage.

6. vA,direet-acting engine having a differatively'small area at the tool end thereof and having -a constantly-admitted pressure acting upon the smaller area, a port adapted to IIS - ential piston provided with a relatively larga area at the head end. of the ovlinder and a rel cylinder having a differential piston, means Aalbe opened to the pressure'on rearward piston movement and closed thereto on forward movement thereof, a passa e connecting said port with the head end of t e cylinder, a differential valve controlling said passage and presenting its-larger area to the pressureintermittently entering said passage and having its smaller subjected to a constant pressure, and an exhaust-passage also connected with the head end of said cylinder, said valve being normally held by the constant pressure to open the head end of said cylinder to said exhaust-passage and close the same to said connecting-passage, but interniittently moved to close the said exhaust and admit pressure to the head end. of said cylinder.

7. An engine having a dillerential piston, means for constantly admitting pressure to the smaller area thereof, a pressure-passage connecting the constant -pressure cylinder end with the opposite end thereof, said passage being opened or closed to pressure by movement of the piston, a dili'erential valve controlling said passage, an exhaust-passage for said opposite cylinder end, and means dependent nponthe expansion of the pressure on movement of the piston toward the constant-pressure cylinder end for opening the said exhaust passage.

8. A direct-acting engine provided with a for constantly admitting pressure to the smaller area of said piston, a passage formed in the cylinder-Wall and connecting the opposite ends of said cylinder, and a differential valve in said passage, said piston upon its stroke in one direction being adapted to open said passage to the pressure and move said valve to admit motive illuid to the opposite cylinder end, and upon its opposite 1novement to cut oil' fluid-pressure from said pas and permit said valve to be shifted to open said opposite cylinder end to'the exhaust. I v

9. A direct-acting engine provided with a differential piston having pressure constantly admitted to the smaller areathereof, a pas.

sage connecting the opposite ends of the cylinder for the intermittent achnission of pressure to the larger piston area, and a valve in said passage, said piston on movement inone direction being adapted to open said passage to pressure and to move said valve to admit pressure to the intermittent-pressure end of said cylinder, and on movement in the opposite direction to close said passa e to pressure and permit movement of the va ve in the op- )osite direction to o eri the said intermittent- 1 pressure cylinder end to the exhaust.

10. A direct-acting engine providedwith a diiiereriiial piston, the smaller area of which is subjected to a constantly-acting pressure, a pressure-passageleading from the constantpressure end of said cylinder to the opposite easier end thereof, a differential valve controlling said passage and constantly pressed toward a position Where it acts to exhaust pressure from the larger piston area hile closing the same to said pressure-passage, the larger area of said valve being exposed to the pressure admitted to said pressure-passage.

11. A direct-acting engine having a differential piston provided with a relatively large area at the head end of the cylinder and a relatively small areaat the tool end thereof,

and having constantly-admitted pressure acting upon the smaller area, a port adapted to be opened to pressure on rearward pis ton movement and closed thereto on forward movement thereof, a passage connecting said port with the head end of the cylinder, a differential valve controlling said passage and presenting its larger area to the pressure intermittently entering said passage, and an exhaust passage also connected with the head endof said cylinder, vsaid valve being constantly pressed to open the head end of said cylinder to said exhaust-passage and to close the same to said coimecting-passage, but intermittently moved through the pressure admitted to said connecting-passage to close the said exhaust and admit pressure to the head end of said cylinder.

12. A direct-acting engine provided with a cylinder having a dili'erential piston having a constant-pressure area, a passage. formed in the cylinder-Wall and connecting the opposite ends of said cylinder, a dii'ierential valve in said passage, said piston on movement in one direction being adapted to open said passage and move said valve to admit linirtpressure throu h the valve and. assa e to one end oi said cylinder and upon its opposite movement to cut oil fluid-pressure. from said. passage and permit said, valve to he shifted to opensaid cylinder end to the exhaust.

13. An engine having a'rliiierential piston and provided with means for constantly admitting pressure the smaller piston area, a port adapted to he opened to the pressure on piston movement in one direc- IOC tion, but closed thereto on movement in the opposite direction, port with the opposite e diilerential valvecentre and presenting its lar er 0 he pressur intermittently enter: d pas go a .d having its smaller area soojected to constant pressure, and an exl .ssa l mally held by the c i to open said cylinder to the exhaust-passage and close the same to said but intermittently moved to close the said exhaust and admit ssure-to the said spine cylinder end. .1-

14. .An engine provii piston, means for constantly admitting pressure to one end of said cylinder, at pressurepassage connecting said constant-pressure we connecting said the cylinder, a said passage connecting-passage. :1

cylinder end with the opposite cylinder end for the intermittent admission of pressure thereto, a valve controlling said passage and havinga pressure area alternately exposed to the constant-pressure side of the piston and the intermittent-pressure side thereof.

In testimony-whereof we have signed our i names to the specification 1n the presence of two subscribing Witnesses.

ALBERT BALL. THOMAS OFFICER. Witnesses:

LEE A. KNIGHTS, GEO. S. BURRILL. 

